Details

[Home]

Issue of the Implementation # L0009

Brief

drivers/net/znet.c: Sleeping function called from invalid context

Detailed Description

Driver drivers/net/znet.c might sleep in atomic context, because it calls free_dma under claim_dma_lock: .drivers/net/znet.c: 

 168 static int znet_request_resources (struct net_device *dev)
...
 189        flags = claim_dma_lock();
 190        free_dma (znet->tx_dma);
 191        release_dma_lock (flags);
...
Path to might_sleep macro from znet_request_resources:
  • znet_request_resources calls free_dma at arch/blackfin/kernel/bfin_dma_5xx.c:181
  • free_dma calls might_sleep arch/blackfin/kernel/bfin_dma_5xx.c:195

    • Possible solutions

    drivers/net/znet.c |    8 --------
 1 files changed, 0 insertions(+), 8 deletions(-)

diff --git a/drivers/net/znet.c b/drivers/net/znet.c
index a0384b6..b423473 100644
--- a/drivers/net/znet.c
+++ b/drivers/net/znet.c
@@ -169,7 +169,6 @@ static void znet_tx_timeout (struct net_device *dev);
 static int znet_request_resources (struct net_device *dev)
 {
        struct znet_private *znet = netdev_priv(dev);
-       unsigned long flags;
 
        if (request_irq (dev->irq, &znet_interrupt, 0, "ZNet", dev))
                goto failed;
@@ -187,13 +186,9 @@ static int znet_request_resources (struct net_device *dev)
  free_sia:
        release_region (znet->sia_base, znet->sia_size);
  free_tx_dma:
-       flags = claim_dma_lock();
        free_dma (znet->tx_dma);
-       release_dma_lock (flags);
  free_rx_dma:
-       flags = claim_dma_lock();
        free_dma (znet->rx_dma);
-       release_dma_lock (flags);
  free_irq:
        free_irq (dev->irq, dev);
  failed:
@@ -203,14 +198,11 @@ static int znet_request_resources (struct net_device *dev)
 static void znet_release_resources (struct net_device *dev)
 {
        struct znet_private *znet = netdev_priv(dev);
-       unsigned long flags;
 
        release_region (znet->sia_base, znet->sia_size);
        release_region (dev->base_addr, znet->io_size);
-       flags = claim_dma_lock();
        free_dma (znet->tx_dma);
        free_dma (znet->rx_dma);
-       release_dma_lock (flags);
        free_irq (dev->irq, dev);
 }

    Component

    linux-kernel 2.6.31

    Accepted

    http://lkml.org/lkml/2009/10/7/317
    commit

    Status

    Fixed in kernel 2.6.32

    [Home]

    »